1. Field of the Invention
The subject invention relates to a heat exchanger drain assembly for selectively draining a fluid from the heat exchanger.
2. Description of the Prior Art
Heat exchangers, such as automotive radiators, include a heat transfer area having a plurality of tubes and corrugated fins and a manifold mounted to each end of the heat transfer area. Fluid, such as radiator coolant, flows through the tubes and manifolds to facilitate an exchange of heat to reduce the temperature of the fluid. At times, the radiator coolant is replaced. A drain port is typically provided at the bottom of one of the manifolds. A plug is disposed in the drain port wherein the plug may be removed, or partially removed, to open the drain port and allow the fluid to flow out of the radiator. U.S. Pat. No. 4,193,575 discloses a radiator drain assembly having a partially removable plug. Alternatively, an outlet hose, which is connected to one of the manifolds, can be detached which allows the radiator coolant to flow out of the radiator. Hence, during certain situations the coolant can be removed from the radiator without the use of the drain port.
Radiator manifolds have been traditionally made of metal with an internally threaded drain port. The plug has a number of seals and external threads which mate with the internal threads of the drain port. The plug and drain port interconnection, however, is often plagued with parts that leak when initially assembled as well as leaks at the vehicle installation stage. Further, this interconnection is prone to failure due to corrosion of the metal parts over time. Often times a corroded plug cannot be easily released or cannot be removed without causing permanent damage to the radiator. Recently, the manifolds of automotive radiators have been formed of plastic so as to reduce the weight of the radiator and the cost of manufacture. In addition, these plastic manifolds are not subject to corrosion damage. An example of a radiator having a plastic manifold is disclosed in U.S. Pat. No. 4,449,692. However, even with the plastic manifolds the plugs are prone to leakage, which creates unnecessary repair and replacement of the plug and/or radiator.
In addition, radiator coolants have been improved such that these coolants have a long service life and may not require changing during operable life of the vehicle. Hence, the drain port and plug leakage is particularly bothersome in that the plug and coolant must be replaced even though the coolant is within its operable life.
Accordingly, it would be desirable to develop a drain port and plug interconnection that is leak tight during initial assembly and vehicle assembly, and remains leak tight over time while still allowing selective draining of the manifold through the drain port when needed.
A heat exchanger having a heat exchanger drain assembly comprising a manifold or tank defining a reservoir for storing fluid therein. A drain port is mounted to the manifold and is in selective fluid communication with the reservoir for selectively draining the fluid from the manifold. In the preferred embodiment, a plug is selectively disposed within the drain port preventing fluid from draining from the manifold and being removable from the drain port for allowing fluid to drain from the manifold. A frangible wall is disposed between the drain port and the reservoir to close the drain port and prevent fluid communication between the drain port and the reservoir. The frangible wall is fracturable to provide the fluid communication between the drain port and the reservoir for draining the fluid from the tank.
Accordingly, the subject invention provides a heat exchanger with a nonfunctioning drain port to ensure leak free use for the life of the radiator. In addition, the subject invention incorporates a frangible wall which can be fractured to allow a fluid, such as radiator coolant, to flow out of the radiator.